I'm very late to answer it. But, I would like to share one example, which I only thought of today. If I told you to cut a piece of paper with dimensions 5m by 5m, then surely you would do that. But suppose I ask you to cut 1000 pieces of paper of the same dimensions. In this case, you won't do the measuring 1000 times; obviously, you would make a frame of 5m by 5m, and then with the help of it you would be able to cut 1000 pieces of paper in less time. So, what you did was make a framework which would do a specific type of task. Instead of performing the same type of task again and again for the same type of applications, you create a framework having all those facilities together in one nice packet, hence providing the abstraction for your application and more importantly many applications.

框架为特定的问题领域提供功能/解决方案。 定义来自wiki:

计算机中的一个软件框架 编程，是一种抽象 哪个公共代码提供泛型 功能可以选择性地 由用户代码覆盖或专门化 提供特定的功能。 框架是一种特殊情况 它们是软件库 代码包装的可重用抽象 在定义良好的应用程序中 编程接口(API)，然而他们 包含一些关键区别 区分它们的特征 普通的图书馆。

从技术上讲，您不需要框架。如果你想做一个非常非常简单的网站(想想1992年的网页)，你可以用硬编码的HTML和一些CSS来完成。

如果你想做一个现代的网络应用，你实际上也不需要使用框架。

You can instead choose to write all of the logic you need yourself, every time. You can write your own data-persistence/storage layer, or - if you're too busy - just write custom SQL for every single database access. You can write your own authentication and session handling layers. And your own template rending logic. And your own exception-handling logic. And your own security functions. And your own unit test framework to make sure it all works fine. And your own... [goes on for quite a long time]

然后，如果您确实使用了一个框架，您将能够从优秀的、通常是同行评审的、经过很好测试的其他开发人员的工作中受益，他们可能比您更好。您可以快速构建想要的内容，而不必花费时间构建或过于担心上面列出的基础设施项目。

您可以在更短的时间内完成更多的工作，并且知道您正在使用或扩展的框架代码很可能比您自己做得更好。

那么成本呢?花点时间学习框架。但是，正如几乎每个web开发人员都会证明的那样，花时间学习从使用你选择的任何框架中获得大量(真的，大量)好处是绝对值得的。

除了定义(有时只有在你已经理解的情况下才能理解)之外，还有一个例子帮助了我。

I think I got a glimmer of understanding when loooking at sorting a list in .Net; an example of a framework providing a functionality that's tailored by user code providing specific functionality. Take List.Sort(IComparer). The sort algorithm, which resides in the .Net framework in the Sort method, needs to do a series of compares; does object A come before or after object B? But Sort itself has no clue how to do the compare; only the type being sorted knows that. You couldn't write a comparison sort algorithm that can be reused by many users and anticipate all the various types you'd be called upon to sort. You've got to leave that bit of work up to the user itself. So here, sort, aka the framework, calls back to a method in the user code, the type being sorted so it can do the compare. (Or a delegate can be used; same point.)

我算对了吗?

一个框架帮助我们使用“已经创建的”，一个比喻可以是，

把地球上的物质想象成编程语言，

举个例子，“相机”是一个程序，你决定创建一个笔记本。你不需要每次都重新创建相机，你只需要使用earth框架(例如技术商店)将相机并将其集成到你的笔记本电脑中。

维基百科(软件框架)的摘要(第一个谷歌点击顺便说一下)解释得很好:

A software framework, in computer programming, is an abstraction in which common code providing generic functionality can be selectively overridden or specialized by user code providing specific functionality. Frameworks are a special case of software libraries in that they are reusable abstractions of code wrapped in a well-defined Application programming interface (API), yet they contain some key distinguishing features that separate them from normal libraries. Software frameworks have these distinguishing features that separate them from libraries or normal user applications: inversion of control - In a framework, unlike in libraries or normal user applications, the overall program's flow of control is not dictated by the caller, but by the framework.[1] default behavior - A framework has a default behavior. This default behavior must actually be some useful behavior and not a series of no-ops. extensibility - A framework can be extended by the user usually by selective overriding or specialized by user code providing specific functionality. non-modifiable framework code - The framework code, in general, is not allowed to be modified. Users can extend the framework, but not modify its code.

您可能“需要”它，因为它在开发应用程序时为您提供了一个很好的快捷方式，因为它包含了许多已经编写和测试过的功能。原因与我们使用软件库的原因非常相似。